OBJECTIVE: To assess the effectiveness of an enhanced implementation system for operationalizing a widely disseminated paraprofessional model of home visiting to prevent child abuse and neglect in at-risk families of newborns, in 1) reducing malleable family risks for child maltreatment; 2) preventing child abuse and neglect; and 3) promoting child health and development from birth to 2 years. BACKGROUND: 20-30% of children are born into families with multiple malleable risks for child neglect and abuse. If not addressed, these risks can compromise parenting, adversely influencing child outcomes. Hawaii's original Healthy Start Program (HSP) model has been disseminated in 39 states. It comprises: 1) population-based screening/assessment to identify at-risk families of newborns; and 2) home visiting by trained paraprofessionals and linkage with primary care and other services to reduce malleable risks for child maltreatment, prevent maltreatment, and promote child health and development. In Hawaii, results of our first RCT motivated refinement of the HSP model and implementation system, and greater integration of liSP services with pediatric primary care (the Medical Home, or MH). AIMS: (1) To develop and pilot test two modifications to the implementation system: performance criteria and fidelity measures. This work will build on activities now underway, including a national survey of existing approaches, qualitative and quantitative studies of HSP knowledge and attitudes, HSP record review to measure current service quality, and consultation with experts to develop core competencies. Building on this, we will develop and pilot test methods to assess home visitor skills directly and to generate timely staff member-specific profiles of performance relative to standards and norms. (2) To conduct a quasi-experimental study to assess the impact of these modifications on: a) actual delivery of home visiting services; and b) program impact on family functioning, parenting, and child outcomes. This will involve: random assignment of HSP sites to intervention and control groups; enrollment of a representative, population-based sample of 240 at-risk families of newborns; baseline measurement of risk and protective factors; and follow-up at 1 and 2 years to measure outcomes. Parent outcomes relate to family functioning and parenting, e.g., risks for maltreatment, observational and self-report measures of maltreatment. Child outcomes include social development and behavior. We hypothesize that a) the enhanced implementation system improves actual delivery of home visiting services; b) the enhanced implementation system improves HSP impact on family functioning, parenting and child outcomes; and c) HSP impact on family functioning and parenting mediate its impact on child outcomes.